At present, numerous oil-processing, petrochemical and coking plants of industrially developed countries generate over two million tons of acid waste a year, such as spent sulfuric acid, sludge and sulfuric-acid discharges.
The presence of such waste causes high transportation costs and allocation of large areas for waste disposal.
In addition, such products are hard to utilize. Very often they contain components of low biochemical oxidizability, pollute the atmosphere with sulfur dioxide, and ground water and soil - with sulfuric acid.
The development of organic compound oxidation plants, with a view to producing boiler fuel, is an urgent need in view of the current shortage of petroleum products and fuel in a number of countries.
Apart from that, the existing plants for the purpose suffer from high energy use and metal consumption, difficulties in assembly and maintenance, and large working areas that are necesary.
There is known in the art a plant for producing fuels, road and construction asphalts, which utilizes for sulfuric acid oxidation of a mixture of sludge with oil tar or flux oil upon heating (cf., U.S.S.R. Inventor's Certificate No. 165,975, class C 10 C 3/04 "Bulletin of Inventions, Discoveries, Industrial Designs and Trademarks" N 20 published in 1964).
This prior art plant includes an oxidizing reactor, a furnace for heating the reactor, a separator for separating particles of products from the vapor-gas phase, and an absorber.
The prior art solution suffers from high energy- and metal consumption, batch nature of the process, lengthy time required for breaking the froth formed in the reactor, all of which affect the plant efficiency. The absence of a device for dispersing sulfuric acid in the sludge-oil tar mixture causes inadequate contacting of the starting reactants, which results in partial coking of the products and clogging of the reactor and pipelines with coke.
There is also known a plant for producing asphalts from sludge or directly distilled oil tar, comprising vessels for sludge and directly distilled oil tar, a mixer for mixing them, a reactor, a furnace for heating the reactor, a separator for the separation of vapor-gas mixture, an absorber, a cooler and pumps (cf., Neftianaya i gazovaiya promyshlennost-Oil and Gas Industry Magazine, No. 2, 1969, pp. 45-47).
Said prior art solution fails to provide for adequate contacting of the starting reactants because of the imperfection of the mixing device.
In addition, said prior art plant suffers from high energy and metal consumption and is characterized by the batch nature of the process.
Corrosion and deformation of the reactor occur in the prior art plant due to high temperatures and their considerable difference over the height of the apparatus, thus resulting in reduced service life of the plant.
Since the reactor is heated with smoke gases, its walls become overheated, which results in local coking of the reaction mass.
There is further known in the art a plant for low-temperature decomposition of sulfuric-acid waste, using a Miley retort (cf., Miley G.G., Petroleum Refiner, published in 1955, Vol. 34, No. 9, pp. 138-141).
The plant consists of a mixing conveyor, screw hoist, retort, cyclone, mixers, vessels, separator, a hopper for coke, cyclones, furnace, levelling conveyor, and scraper conveyer.
The prior art plant suffers from marked corrosion and erosion of moving scraper conveyors, as well as from high energy and metal consumption. The plant requires a large working area, is difficult to maintain, unreliable in operation and is inefficient.
Also known is an organic compound oxidation plant comprising a vessel for liquid-phase oxidizer, a vessel for organic compounds, a mixer for mixing organic compounds with the liquid-phase oxidizer, a furnace for heating organic compounds, a reactor for oxidizing organic compounds, a cooler and pumps, chosen by the present inventors as prototype (cf., U.S.S.R. Inventor's Certificate No. 321,536, class C 10 C 3/12, "Bulletin of Inventions, Discoveries, Industrial Designs and Trademarks" N 35 published in 1971.
However, said latter prior art plant is characterized by high metal- and energy consumption, low efficiency, long duration of the process, complicated control and maintenance and low technical and economic parameters, as well as a required large working area.
In addition, said prior art plant lacks units and devices providing for fine dispersion of a highly viscous liquid-phase oxidizer over the volume of organic compounds.